Ballast tamping apparatus



BALLAST TAMPING APPARATUS 15 Shee'ts-Sheet 1 Original Filed Oct. 8. 1948 WITNESSES N r. [NE 1131230152 z: 177116 l/ J & 2/ flare/Merl 22 /1, %M 20 7%, A BY w I ATTORNEYS.

15 Sheets-Sheet 4 Original Filed 001.. 8. 19518 Q NR NN NN INVENTORS J'laregzwd ggZz,

ATTORNEYS.

WITNESSES INVENTORS. My 4; J'm/memflmsym flare/we cl fiegglz,

July 21, 1953 s. R. HURSH EIAL Re. 23,687

BALLAST TAMPING APPARATUS Original Filed Oct. 8, 1948 15 Sheets-Sheet 7 @16 By I TTORNEYTS.

July 21, 1953 s. R. HURSH ETAL BALLAST TAMPING APPARATUS 15 Sheets-Sheet 8 Original Filed Oct. 8. 1948 g; VITNESSi(L% July 21, 1953 s. R. HURSH ETAL 23,637

BALLAST TAMPING APPARATUS Original Filed Oqt. 8. 1948 15 Sheets-Sheet 9 WITNESS INVENTORS.

J Z Q ZMZ W A mm A T'IORNEYS.

y 3 s. R. H URSH ETAL Re. 23,687

BALLAST TAMPING APPARATUS Original Filed Oct. 8, 1948 15 Sheets-Sheet l0 W l TNESSE Z r July 21, 1953 s. R. HURSH ETAL BALLAST TAMPING APPARATUS Original Filed Oct. 8. 1948 15 Sheets-Sheet 12 A m g m 7 121 150 147.9 I r /zfiz 7.5] 1 J53 145 v A, ;F1a217 FIGEML A MW A TTORNE Y5 "July 21, 1953 s. R. HURSH ETAL .Re. 23,687

BALLAST TAMPING APPARATUS Original Filed Oct. 8. 1948 15 Sheets-Sheet 14 HGL 22. 41" l WITNESSES INVENTORIS'." M & famuelliflrms hnfi flare/we J Beg/L,

July 21, 1953 s. R. HURSH ETAL BALLAST TAMPING APPARATUS Original Filed on. a. 1948 15 Sheets-Sheet 15 INVENTORSI Samuelfl.]lurs ]z& 'larenceclfielyk, BY 6%: 02

ATTORNEYS.

ZTNESSES 0% 2 -44% Reissued July 21, 1953 -IUVNITED ATE'S'J NT OFFICE g.

' Samuel-Rubella, Bala Cynwyd, and Clarence I. Reigh, Altoona, Pa.; said Belg]: assignor tosaill Original No. 2.5,324, dated Februar-y'zii, 1952, Serial No. 53,518, October 8, 194 8. Application for reissue December 8, 1952, Serial No. 384,861

Matter in heavybrackets t 1 appears in the original patent but forms no part of "-39 cam. (on. 104-12) reissue specification; matter prlntedin italics indicates the additionsmade by reissue.

This inventionfrelates to ballast tampln anpar'a'tus, that is to say, to apparatus or machines intended for use in railway trackmaintenanceto tamp the rail supporting ties. I

As is well known to .those experienced in railway track maintenance, a track, structure in which the ties are tamped with power tamplng devices, particularly tampers of the pneumaticv gun type, not only has greater stability, but is much more durable than one tamped by hand with tamplng picks. Failure of power tamped track to last longer under present day travel and speed conditions is generally attributable to differences in the skill and Judgment of the men operating the tempers, irregularities or changes in' the pressure of compressed air or other power supplied to the tempera, and to disturbances to effective work previously done when the tampersare moved to new positions. We are aware that various forms of apparatus or machines have been designed heretofore to carry out tie tamplng operations with a view to eliminate the deficiencies of manual tamplng. but these have been found inadequate since they depended upon, compression of the ballast in the cribs or spaces between the ties, or upon the vibration of the stone to displace it laterally in the cribs without assurance that it would be compacted beneath the,

ties at the regions of rail support as is essential to a well constructed track. The chief aim of our invention is to overcome the variousdimculties and drawbacks pointed out above in connection with prior methods and apparatus employed in tie tamplng, by enabling tamplng to be accomplished economically and efliciently, without the necessity for dependence upon human skill or Judgment or the employment of specially trained help, in such a way that the ballast is effectively packed beneath the ties at the end regions or areas of rail support, thereby avoiding the formation of what is known as "center bound" track in which the ties are subjected to breaking strains incident to overtravel of the rails by heavy trains at high p dfl- The. foregoing desiderata are realized in practice,-as hereinafter more fully set forth, through provision of a tamplng apparatus in the form of a platform car from which unit groups of powered tamplng devices or pneumatic guns supported over' the rails of the track for concurrentoperatl'on from opposite sides of theties both inwardly and outwardly to limited extents, said devices having laterally directed tamplng bits capableof underreaching the ties to pack the ballast beneath them. Incorporated with the car are means whereby, under manual control, those tamplng devices of the .respective unit groups operating outwardly beyond the rails are moved back and forth .contrariwise relative to those operating inward of the rails during ,the tamp g, and at the same time swung as they approach each other so that all of them are angled toward the rail supporting areas of the ties; manually-controlled power actuated means for retracting the tamplng devices of the respective groups for withdrawal of their bits from beneath the ties and for raising them clear of-the track; means automatically operative to interrupt the flow of mptivating power medium to the tamplng devices of the respective groups during their elevation as aforesaid and restoring the flow of the power medium when they are subsequently lowered; manuallyrespective rails at the desired level or levels in the vicinity of the tie or ties being tamped, or raising the car bodily from the rails in preparation for its removal from the track; auxiliary wheels at opposite ends of the car under which supplemental rails may be placed crosswise of the track rails so that the car can be rolled from the track on said supplemental rails; and power means with a selective control whereby the main wheels can be driven for propulsion ofthe apparatus from one location to another on the track, or the auxiliary wheels driven to remove the car from the track on the supplemental rails and vice versa.

2 Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein; Fig. 1 is a broken out view in side elevation of a ballast tamplng apparatus conveniently embodying our invention, with the tamplng devices and the track lifting devices raised to inoperative positions clear of'the track.

vation with said tamping devices i operative position.

Fig. 7 is a view like Fig. with thetamping devices partly raised from operative position Fig. 8 is a fragmentary view, likewise on a larger. scale, showing one of the tamping units in top plan.

Fig. 9 is a view like Fig. 8 with the tamping.

taken as indicated by the angled arrows XIV- XIV in Fig. 13.

.Fig. is a fragmentary broken out view plan showing more particularly the powercr. mechanism for propelling the. apparatus.

Fig. 16 is a fragmentary detail view in section taken as indicated by the angled arrows XVI- XVI in Fig. 15. I

Fig. 1'! is a fragmentary view in cross section on a larger scale taken as indicated by the angled arrows XVIIXVII in Fig. 1 and showing one of the component devices of the means provided for lifting the track.

Fig. 18 is a view of the track lifting device as seen from the right of Fig. 17, with a portion broken away and shown in section.

Fig. 19 is a view, partly in elevation and partly in vertical section, corresponding to Fig. 1''! showing the track lifting device inoperative position in readiness to elevate the track.

Fig. 20 is a horizontal section taken as indicated by the angled arrows xx xx in Fig. 19.

Figs. 21, 22 and 23 are perspective views of various of the component parts of the track lifting device.

Fig. 24 is a fragmentary view in top plan, showing an alternative mechanism for shifting the tamping units longitudinally ofthe car.

Fig. 25 is a fragmentary view in transverse section taken as indicated by the angled arrows XXV-XXV in Fig. 24.

As exemplified in Figs. 1-5 of these illustra-- tions, our improved ballast tamping apparatus is in the form of a car with an elongate platform I overlaid upon a horizontal frame 2 of structural steel, and with flanged supporting wheels I adjacent opposite ends thereof for travel on the rails R of a railway track, and whereof the axles l and I are journalled in suitable bearing brackets 5 pendent from said frame. Midway of the length'of the car. the platform I and the frame 2 are recessed inwardly from opp flite sides to afford clearance spaces 0 and I (Fig. 2) which are occupied by tamping units respectively designated and 9. Except for being oppositely arranged transversely of the car, the tamping units are identical in construction and operation. This being so, the description about to follow of the unit 8 separately illustrated on an enlarged scale in Figs. 6-14, will be considered to hold also for the unit 9. As shown. the tamping unit I com- 4 noted that the tamping devices II are disposed for operation from one side of the track ties T inwardly of the track rail R, and thedevices l2 disposed outwardly beyond the rail R. to op rate from the other side of the tie. The main carriage II has spaced side members It and I1 connected at opposite ends and at thecenter by cross members II, II and 20 respectively. Downwardly and inwardly retroverted flange portions 2| and 22 (Figs. 5 and 10) of the end and center cross members ll and 20 of the main carriage I0 underlap the upper flanges of oppositely facing parallel channel longitudinals 22 and 24 of the carframe 2, the main carriage being thus not only held to. but guided for movement along said frame longitudinals. For the purpose of shifting the main carriage I. to transfer the tamping units for operation from one track tie T to another, there is provided at the corresponding side of the car,

a screw spindle '25 which is rotatively supported in fixed bearings 28 and 21 respectively on frame 24 (see Figs. 2 and i0) and on said carriage, and which is arranged to be power driven by a reversible air motor 22, see Figs. 1 and 6. in a manner described later. In turn shiftable within the main carriage in are two smaller or secondary carriages 28 and I! from which the pairs of tamping devices II and i2 are directly supported respectively. The secondary carriages 29 and II are also identical in construction butreversely arranged as to position in the main carriage, each having at opposite ends thereof, shoes 22 and 33 which are slidingly engaged in the channel hollows of the side members It and II of said main carriage. The shoes 32 and 33 are welded fast to vertical channel bars 35 and 36. see Figs. 6 and 7, which bars extend both above and below said shoes and which at their lower ends are connected at the front and rear by outwardly bowed cross members 11 and it. At about the level of the shoes 32 and 33. the vertical bars 35 and 36 are connected at the rear only by a single crosswise bar 29 having adjacent its opposite ends, longitudinally extending slots 40 and II for a purpose presently explained. Movable up and down in the channels 35. 26 of the secondary the frame 45 with their ends slidingly engaged in the channel hollows in the side members l8,

l! of the latter, are cross heads 50. At their centers, these cross heads so are connected to the lower ends of the piston rods ii of air cylinders 52 rigidly supported between clamp bars 52 which extends cross wise between the upright bars I! and It ofthe secondary carriages 28, 29 near their tops. The downward limit of movement of the frames 45 is determined by engagement offlxed lugs a and 49a on their side members II and ,4! with stop bolts 54 removably secured by cotter pins in lugs 35a and its on the vertical bars I! and 36 of the carriages 29 and 82. see Figs. 5, 6, '7 and 10, 11. The tamping devices ll, I2 are connected by transverse pins I! and 58 to the lower ends of individual square section shafts 51 and it which pass, with capacity for independent rotation and endwise movement, through closely spaced round apertured guides 59, ill and Bi, 82 respectively welded to the vertical channel bars 35 and 35 of the secondary carriages and-through similar apercarriages 28 and 88 are coupled by a lazy tong means consisting of a pair of crossed levers 88 and N which are fulcrumed for independent movement about a stud II upstanding from the center of the intermediate cross bar 28' of the main carriage Ill, and which have pins 88 and 61 in their opposite ends engaging the slots 48 and ii in the cross members 88 of said secondary carriages. As shown in Figs. 6 and 14, the bodies of the tamping devices Ii, ii are formed with lateral projections Na and Ila at their tops which, as the frames 88 are lowered, engage the tops of the bottom cross bars 81 of the frames 48. As a consequence, the device's Ii and I! are canted inwardly toward each other to bring their bits It under the track tie T from opposite sides. Compressed air is conducted to the tamping devices II and II of the respective pairs through flexible tubes 88 and 88 which are connected to T fittings 18 in communication, by way of ducts H (Figs. 6 and 12) in the cross heads 88, with upwardly, extending pipes 12. As shown, these pipes 12 pass freely through guide blocks 18 in the intervals between the lower cylinder clamping bars 88, and interposed in each of them is a control valve 14. To the operating stem of each valve 14 is secured a bifurcated lever II, the extremities of which are adapted to be alternately engaged by a pin 18 extending transversely of the corresponding pair of the upper cylinder clamp bars 88, see Figs. 1 and 8 to open the valve when the frame 45 is lowered and to close it when said frame is raised. The vertical shafts I1, 88 are provided with collars 88 and 8! which bear upon the tops of the cross beams 88 as shown in Fig. 6. Accordingly during the rise of the cross beams 88. the shafts 81, 88 are carried along with said beams. Freely pivoted to studs at the fronts of the verticals 48 and 48 of the frame 48 are triangular dogs 82 and 88 which, when said frame and the cross head are fully lowered, are held in the positions in which they are shown in Fig. 6. by lugs 84 respectively at the fronts of the cross heads 58 adjacent the edges of the verticals l8. 48. In these positions, the upwardly swung ends of the dogs 82 and 88 underreach the outer ends of lower cross members 81 connecting the vertical channel bars 85 and 86 of the secondary carriages. Accordingly, when the cross beams 88 move upward, the frames It are prevented from following for atime until the dogs 82, 88 are cleared by the lugs 84 on said beam as in Fig. 7. As the cross heads 80 continue to rise thereafter, the collars 88', 8| on the shafts I1 and 88 eventually contact the under sides of the upper cross members It of the frames 88 so that the latter are finally raised with said heads to the position shown in Fig. l to bring the tamping devices clear of the ties and track bed when the car is to be moved on the rails R.

Disposed in the intervals between the des 88, G8 and GI, 62 previously referred to and provided with square openings for sliding passage of the square shafts 51 and 88 through them, are bifurcated levers 81 and 88 the extremities of which are adapted to be acted upon alternately by pairs of-tamping devices I I, it directly supported by them respectively, the carriage. 28 having the greater throw for tamping of the ballast beneath the tie outward from the rail to the tie end, and the carriage 88 having the lesser throw inwardly of the rail. This differential action is purposely utilized to preclude center bound track and to thereby avoid tie breaking as when unequal settling of the track takes place by reason of the latter condition. It is to be further noted that.

. by action of the projections 88 and 88 on the main carriage 8 upon the bifurcated levers 81 and 88 as the supplemental carriages are moved: toward each other during the tamping from the position end.

projections 88 and 88 on the 'main carriage ll,

during shifting of the secondary carriages in 091 posite directions, to automatically and concurrently turn said shafts to angle the tamping tools Ii and f2.

It is to be especially observed from Figs. 8 and 9 that the proportioning of the lazy tong levers 88 and 64 is such as to determine differential shifting of the secondary carriages I8 and 88 and the of Fig. 9 to the position of Fig. 8, the shafts 81 and 88 are turned to swing the tamping devices H and I! in the direction of the arrows in the latter illustration about their pivotal connections with the square rods 57 and 58 which thus act as positive guide means, so that when the position of Fig. 8 is reached, said devices will all be'angled radially toward the rail supporting area of the tie to effectively pack the ballast beneath-the tie at that region. The tamping unit 8 is of course controlled and operated in precisely the same way and at the same time to pack the ballast beneath the rail supporting area of the tie at the opposite -To enable simultaneous shifting of the secondary carriages 28, 30 of both tamping units I and 8 regardless of the position occupied by the main carriages along the car, we have provided means as follows: Journalled in bearing brackets 88 upstanding from the side members I6, ll: of the main carriages i0 adjacent their inner ends, are rock shafts 88 with clevis ended arms shavin pins at their inner ends engaged in vertical slots 88 in wing plates 98 secured to the verticals 3 88 of the inner carriages of the secondary pairs. The arms 81 are longitudinally slotted for engagement by pins in the swinging ends of levers I88 whereof the fulcrum hubs have squared apertures slidably fitting square section shafts llll with the cylindrical ends rotatively supported in pendent brackets I02 on the car frame. As shown in Fig. 8, the fulcrum hubs of the arms 'Iflll are engaged by clevised projections I08 on the inner cross members ill of the main carriages and are thereby slid along the shafts llll as the main carriages are shifted from one position to another on the car. Fixed-arms I05 on the shafts "ii are connected by links I06 with an arm llll on a short transverse shaft I08 whereof the opposite ends pass through bearing apertures in apair of closely spaced supplemental longitudinals III at the center of the car frame 2. The shaft I88 is operable by means of a hand lever llowhich extends up through a clearance opening in planking or decking HI laid over the car frame longitudinals I 08. Thus, by virtue of the construction just described, the secondary carriages 28 and 88 of the two tamping units 8 and 8, can be concurrently shifted back and forthwith four tamping devices operating simultaneously along each end of the tie to pack the ballast beneath the latter from opposite sides. 1-

Supply and exhaust of compressed air to the lift cylinders 82 of the respective tamping units 8 and 8 is controlled by separate manually operable valves ll! convenient of access from the center of the car platform 1. Leading from the respective control valves H2 are pipes H8 which connect with cross pipes H4 extending between the top and bottom ends of the cylinders. The valves H2 may be of any approved commercially case? available type by which the air can be admitted to the tops of each pair of the cylinders 62 and concurrently exhausted from the bottoms thereof when the tamping devices are to be lowered into operative posi tion,-and, vice versa, when said devices are to be elevated clear of the track in preparation for movement of the car on the rails R from one location to another.

For the purpose of lifting individual ties from the track bed and holding them level during the tamping, we have provided lifting devices II6 of which there are four, one located adjacent each comer of the car platform. Except for being arranged as rights and lefts at opposite sides of the car, these lifting devices are exact duplicates of each other, so that the following description of one of them will apply equally to the rest. As instanced in Figs. 17-23, each lifting device II6 comprises a slide II6 which is fashioned to hollow box-like configuration from stout sheet metal and which telescopes into a similarly fashioned vertical sheathing guide II1, with shoes H6 at opposite sides thereof slidingly engaged in the hollows of parallel longitudinal guide channels 9 on the car frame 2. Welded to the back of the slide I I6 at the bottom is a block I26 which has a vertical bore for free rotation therein of the lower end of a vertical screw spindle I2I with fixed collars I22 and I26 thereon bearing against the top and bottom of said block. The screw spindle I2I extends up through a hollow head I26 aillxed to the top of the guide H1 and contains a worm wheel I26 which is threadedly engaged with said spindle I2I. As will be seen from Fig. 19, the gear wheel I26 is held against axial movement in the head I26, and meshing therewith is a worm I21 (Figs. 17 and 18) which is ilxeiupon a laterally extending shaft I26 supported for rotation in bearings I26 at the outside of the head I25. At one end, the shaft I26 is connected to a reversible air motor I66, its opposite end being squared as at I260 for application thereto of a hand crank by which it may be manually operated if desired or required. Welded or otherwise aillxed to the back of the slide H6, at the outside, is a bracket III which affords vertical axis bearings for the shafts I62 and II! of a pair of lateral projections or fingers Ill and I36 adapted to engage beneath the head of the track rail R from opposite sides. Pinned to the shafts I62 and I66 directly above the bearing bracket I 6| are intermeshing spur sectors I36 and I61. As shown,-the shaft I62 is square in cross section and extends, with capacity for axial and rotative movement, through a pair of vertically spaced bearing ears I66 c'projecting laterally from the guide element II1.

Engaged between the ears I66 is the boss of rail grippers I36 and I66 to be swung,

through the medium of the intermeshing gear sectors I36 and I31, into and oflateral engagement with the rail R. Movable up and down gwithin and independently of the gripping slide 1 I6 is a leg IlI having a foot 2 at the bottom thereof to contact the track bed between ties T, and also having a lateral projection Ill at the top which is bored and tapped to threadedh' engage the screw spindle I2I. Slidably keyed to the upper protruding end of the screw spindle I2I is a clutch collar 6 which is axially shiftable in a guide bracket 6 on the head I26 for interengagement of teeth Illa at the bottom thereof with teeth I260 on the hub of the worm Bear I26. The clutch collar Ill is shiftable by means of a hand lever Il1 secured to the outer end of a short horizontal shaft Ill which is rotatively supported in the bearing bracket H6, and which, at its inner end, has a collar Ill with an eccentric stud I66 projecting into a circumferential groove I6I at the top' of said clutch collar. When the clutch collar Ill is raised as in Figs. 1'1 and 18, it and the screw spindle III are held against rotation through engagement of a lateral stud I62 adjacent the bottom end thereof with one or the other of two step studs I63 on the bracket. When free of the clutch collar Ill, the worm wheel I26, in rotating will act as a nut to move the spindle I2I vertically. The leg Ill is thereby raised or lowered together with the rail gripper slide II6 depending upon the direction of rotation of wheel I26. On the other hand, when the worm wheel I26 is clutched to the spindle I2I by the collar 6, said spindle will be rotated without aifecting the rail gripper slide H6, and the leg element I will be raised or lowered with the tapped projection Ill at the top thereof acting as a nut on said spindle. The horizontal screw spindle I66. by which the lifting device III is shiftable longitudinally of the car, is threadedly engaged in a bearing bracket I66 projecting from the inner side of the guide II1. From Rig. 2 it will be observed that the screw spindle I66 for each lifting device 'I I6 is rotatively supported at one end in fixed bearings I61 on the car frame 2, and arranged to be driven by a reversible air motor I66. Extending longitudinally of the car at the center, see Figs. 2. 4 and i5, is a [propeller] propelling shaft I66 which is rotatively engaged in bearings I6I at the underside of the car frame 2. The opposite ends of the [propeller] propelling shaft I60 extend into gear housings I62 centrally of the car wheel axles l and l, and secured to them are worms I66 and I66 that mesh with worm wheels I and I66 on said axles. Through a sprocket chain connection I66, the propeller shaft I60 is powered from a reversible air motor I66 mounted on the car platform. The worm wheels I and Ill are normally free on the wheel axles l and l but arranged to be connected thereto by clutch collars I61 and I61 slidably keyed to said axles. The clutch collars I61, I61 are independently operable by separate hand levers I66 and I66 fulcrumed on brackets I69 and I6! on the car platform, and are connected by link rods I10, I16 to bell cranks HI and HI which in turn, are fulcrumed on cross members I12 and I12 of the car frame, with one arm in each instance engaged with a'circumferential groove in the corresponding collar. Aflixed to the car axles are brake drums I16 and I16 whereof the bands I16 and I16" are contractable by short toggle shafts I11 and I11 rotative in fixed bearings I16 and I16 on the car frame. Actuating arms I16 and I1! on the shafts I11 and I11 are connected by link rods I and I60 to opposite ends of a two armed lever Ill and I6! (Fig. 16) amxed to a rock shaft I62 with rotative support in a bracket I66 on the longitudinal I09 of the car frame. While the car is in motion, the brakes are controllable by means of a foot treadle I which is secured to a rock shaft I86 journalled in the car frame longitudinal I06 (Fig. 16), and which has a pendent arm I61 connected at the upper extremity of lever IOI. Free on the shaft I66 is a hand lever III with a sliding latch dog I66 which is adapted to engage with the teeth 10. the clutch collars Ill and III are separately connected to treadles III, III arranged side by side on the mid portion iii of the car platform. Byvirtue of this construction it will be seen that the spindles II can be operated individually by depressing one or the other of the treadles 218, ill or concurrently by depressing both treadles at the same time as desired or required in spottemporarily placed crosswise upon the track rails R. The axles ll! of the auxiliary wheels I", III extend longitudinally of the car i. e. at right angles to the main wheel axles I, l and are rotative in bearing brackets I81 pendent from the transverse end beams it. of the car frame I. To the inner end of one of the auxiliary wheel axles I" at each end of the car is affixed a miter gear pinion III which meshes with a companion miter gear pinion III on the contiguous end of the corresponding car wheel axle I or la.

Whenthecaristobepropelledontherails' R, one or the other or both hand levers Ill, I'I

are thrown to shift the clutch collars Ill, "1'. into engagement with the worm gears I, IN so that one or both of the car wheel axles I, 4' are driven through the [propeller] shaft Ill from themotor it. which, as previously stated, is reversible for travel of the car in either direction. At these times, the auxiliary wheels I85, III will simply rotate idly-by reason of being connected to the axles 4, 4' through the miter gears I, "I. A similar procedure is followed when the car is to be removed from or restored to the track rails R, at which times the wheels I will run idly while the auxiliary wheels III, Ill bear upon the supplemental track rails R. Restoration of the apparatus upon the track rails is accomplished by reversal of the above procedure. The only manual effort entailed in these operations being the placement and removal of the supplemental rails R.

Suitable compressed air delivery piping (not shown) with individual control valves is of course provided in practice for the motor 28 that drives the spindles II by which the tamping units I and 8 are shifted longitudinally of the car, the motors I" that drive the vertical actuating screw spindles I of the lift devices III, the motors III which drive the screw spindles for shifting said lift devices, and the motor I" for propelling the car. The compressed air may be supplied from any appropriate source such as an internal combustion motor compressor unit (not shown) mounted on the platform I of the car.

In the alternate mechanism shown in Figs. 24'

and 25 for shifting the tamping units longitudinally of the car, a single reversible electric motor 28:: is employed, the same being suitably suspended from the car frame 2. A worm ill on the shaft of motor 28:: meshes with a worm wheel 206 which is freely mounted over the abutting inner ends of two axially aligned shafts I". 208 extending transversely of the car. Afllxed to the outer ends of the shafts "1, I" are miter pinions 209 that mesh with companion miter pinions fill respectively on the contiguous ends of the screw spindles fl. Splined on the shafts III, 208 are shiftable clutch collarslll, III

which are urged toward the worm wheel by springs III, I, and which are provided with teeth for engaging corresponding notches atopposite sides of the hub of said wheel. Through bell crank levers ill-2|. and link rods 2", ill,

ting the tamping units.

Our invention is not to be considered as limited to the precise embodiments herein shown and described by way of exempliilcation, since, within the scope of certain of the broader of the appended claims, other modifications and ampliil-' cations are possible. For instance, electrically powered tamping devices may be utilized in lieu of the illustrated pneumatic type, and electric motor devices substituted for raising and lowering the tamping devices from and to the track bed. for propelling the car, and for driving the screw spindles by which the main carriages III of the tamping units I and 9 and the track lifting devices III are shifted longitudinally of the car. As another alternative, the car may be equipped with several pairs of tamping units '8 and I for the tamping of as many ties at one time. In all cases it will be apparent that our' 7 We are thus not only able to effect the tamping quickly and efficiently at a great saving from the standpoint of labor costs, but to insure a for supporting the tamping devices from the platform with capacity to be shifted along the latter from position over one tie to position over another tie and to be raised and lowered from and to operative position relative to the track bed.

2. Ballast tamping apparatus according to claim 1, further including means automatically operative ,to stop the tamping devices as they are raised and to re-start said devices as they are lowered.

3. Ballast tamping apparatus according to claim 1, in which the supporting means for the tamping devices is in the'form of a carriage which can be shifted longitudinally of the platform to transfer said devices, after being raised, for operation from one tie to another.

4. Ballast tamping apparatus according to claim 1. wherein the platform is supported by the ballast beneath a track tie from opposite sides.

thereof with the individual devices of each pair disposed at opposite sides of a track rail;and a carriage shiftable longitudinally of the car for supporting the tamping devices from the platform with capacity for being raised and lowered 

